A SYSTEM FOR DISSOLVED OXYGEN CONTROL IN INDUSTRIAL AERATION TANK

The control system is developed for accurate set-point control of dissolved oxygen concentration in industrial aeration tank based on adaptation of PI controller to time-varying dynamics of the controlled process. The controller adaptation algorithm refers to the process state model-based transfer function that follows changes in process dynamics by up dating the function par ameters with on-line measurements of process variables, and the controller tuning rules developed for typical structure transfer function models. The control system was investigated via computer simulation of the dissolved oxygen concentration set-point control in an industrial aeration tank under process disturbances and set-point step changes. The control system demonstrates fast adaptation of PI controller parameters and noticeably higher accuracy control compared to that of ordinary fixed gain PI controller.